Apr 11, 2016 Apple’s Disk Utility is the first place to start. Reboot your Mac. Select Disk First Aid to test the hard drive for problems. The utility will fix any problems or warn you of a S.M.A.R.T. HFS+ vs APFS Up until recently, HFS+ was the only file system supported by macOS and OS X. However, with the launch of the newest macOS High Sierra, Apple introduced a new drive type called Apple File System (APFS). HFS+ HFS+ was first introduced in 1998 with the launch of Mac OS 8.1 back when Apple made the switch to Intel-based processors. Although HFS+ is supported on all versions of Mac. Dec 17, 2019 The steps below are for one type of issue. This issue is with that of a hard disk drive that is displayed on your Mac but doesn’t give you access to data. First Aid would be the tool you would use if you have to fix this issue. Simply follow the steps below: Visit System Preferences. Launch Disk Utility. Make sure the external hard disk drive. Jun 02, 2020 The app also has options like First Aid, Erase, Restore and Unmount. Using this, I have created partitions on my MacBook very quickly and effortlessly. You can see the easy steps along with screenshots here. Price: Free (In-built) #2. Stellar Mac Partition Manager. With this guide to OS X first aid by your side, you’ll be able to quickly resolve the most-common Mac problems: freezes, crashes, startup woes, and kernel panics.

Summary: First Aid process has failed on external hard drive? In this article, we will tell you what to do if First Aid can't repair external hard drives, SD cards, USB flash drives and more. If necessary, recover lost data from the external hard drive with iBoysoft Data Recovery for Mac to avoid permanent data loss.

Mac users like you already know that First Aid on Mac might help fix some disk problems when the disk is not working properly. However, it sometimes can fail to repair the disk. During the running of First Aid on an external hard drive, one of the following error messages may pop up indicating First Aid operation failure:

'First Aid process has failed. If possible back up the data on this volume. Click Done to continue.'
'First Aid could not unmount the volume for repair. Click Done to continue.'
'First Aid found corruption that needs to be repaired. To repair the startup volume, run First Aid from Recovery. Click Done to continue.'

Note: Only when you are using the external hard drive as a startup disk and run First Aid to repair it, you could see the error message to ask you to run First Aid from macOS Recovery.

Don't worry. This post will help you solve the First Aid not working problem and recover lost data from the troubled external hard drive.

Table of contents: 1. What does First Aid do in Disk Utility?; 2. What to do if Disk Utility's First Aid has failed on external hard drives?; 3. Conclusion

First of all, let's take quick look at what First Aid can do in Disk Utility.

What does First Aid do in Disk Utility?

First Aid in Apple's Disk Utility is a small utility designed to verify and fix minor problems of a drive, such as repairing the drive's data structures, fixing external hard drives not mounting on Mac, external hard drive not readable on Mac and so on. It has the capability to detect and repair the damages to partition map, master directory block, device driver and so on.

But why Disk Utility's First Aid would fail on external hard drives?

Most of the time, First Aid's failure on external hard drives is due to severe disk corruption which was brought about by improper ejection, physical damage, virus infection or other reasons.

In the next section, you will learn what to do if First Aid repairing process has failed on external hard drives.

What to do if Disk Utility's First Aid has failed on external hard drives?

Generally speaking, if you can't run First Aid on an external hard drive to repair it, the solutions left for you to repair the corrupted external hard drive on Mac are limited. We have concluded three methods for you to try one by one, hoping they can repair the corrupted external hard drive successfully without losing data.

Solution 1: Run First Aid one more time

On Apple's official Support page, users are encouraged to run First Aid more than once. First Aid will try to verify and fix the content on the selected volume every time. Therefore, there might be a hope that it works after you rerun it. If you are receiving a constant result saying the process has failed, you can move to the next solution.

Solution 2: Run FSCK command from Single User Mode

FSCK (File System Consistency Check) is Mac and Linux version of CHKDSK command in Windows. It can check the file system and try to repair the damages it finds. FSCK command can be run to repair a boot disk or a non-boot disk. Therefore, if running First Aid on Macintosh HD failed or Macintosh HD could not be repaired in Disk Utility, you can also run FSCK command to repair the startup disk.

However, unlike CHKDSK command in Windows, you can't run FSCK command inside the operating system. You need to exit the operating system and reboot into Single User Mode.

Tips: You won't be able to see this article when you are running FSCK command, so we recommend you write down the steps below especially the command lines for your convenience.

Follow the steps to fix the corrupted external hard drive using FSCK command:

Step 1: Go to Disk Utility, select the corrupted external hard drive, and remember the file system and Device name. In the picture below, the file system in Mac OS Extended (HFS) and Device name is disk3s2.

Step 2: Restart your computer and hold down Command + S keys to boot into Single User Mode.

Step 3: Release the keys until you see white text appears on the startup screen.

Step 4: Wait until you see root#appears at the bottom of the text.

Step 5: Run the following command:

Tips: Remember to replace 'hfs' with the file system on your external hard disk. For example, type fsck_msdos for FAT file system and type fsck_exfat for exFAT file system. Remember to replace disk3s2 with the Device name of your external hard disk too.

Step 6: Wait until the checking and repairing process is completed and run reboot command.

Hopefully, the command has helped you fix file system errors on your external hard drive. If your external hard drive is still not working properly after you reconnect it to the Mac, proceed to the last solution.

Solution 3: Reformat the external hard drive

If you have encountered the First Aid operation failure when trying to fix external hard drives and neither of the solutions above works, the disk is probably severely corrupted. The simplest and most efficient way is to reformat the corrupted external hard drive to make it workable again. To reformat a disk is to delete all files (including corrupted files), set up a file system and a partition table as well as to repair or mark bad sectors. Those are the main factors that cause disk corruption, so to reformat a disk can solve almost all disk problem you may come across. But before that, you'd better back up as many files as possible to another drive, just as Disk Utility suggested.

However, you probably won't be able to back up your files directly from the seriously corrupted external hard drive. In this situation, data recovery software comes for help.

Step 1: Recover as much data as possible with iBoysoft Data Recovery for Mac

iBoysoft Data Recovery for Mac is reliable external hard drive data recovery software for Mac users. It is able to recover deleted or lost data from unreadable/unmountable/formatted/corrupted external hard drives. In addition to external hard drive data recovery, it is also a tool that supports USB flash drive data recovery, SD card data recovery and so on. Moreover, it is a data recovery tool for Mac that supports data recovery for encrypted APFS disks. This software is fully compatible with macOS 10.15/10.14/10.13/10.12 and OS X 10.11/10.10/10.9/10.8/10.7.

Recover lost data from corrupted external hard drives with iBoysoft Data Recovery for Mac

1. Download, install and launch iBoysoft Data Recovery for Mac.

2. Select the external hard drive that First Aid failed to repair and click Next

Mac Drive First Aid App